The aims of this trial are to assess the toxicities of and determine the maximum tolerated dose (MTD) of subcutaneous calcitriol given Day 1-5 in combo with carboplatin (AUC=6) Day 5; to assess the toxicities of and determine the maximum tolerated dose (MTD) of carboplatin Day 5 when given with subcutaneous calcitriol Day 1-5 at a dose one dosage level less than the MTD; to determine the effect of administration of calcitriol on the AUC of carboplatin; and to assess the relationship between the AUC of carboplatin and myelosuppression.